atunci cind nu ai cu cine invata teoria muzicii :(

Smaller instruments, which play notes mainly above middle C, only use the treble clef. These include the violin, flute, clarinet, oboe and trumpet.

But some bigger, lower-pitched instruments, like the bassoon, trombone or cello, have a range which is partly above and partly below middle C. If we only used the treble or bass clefs for these instruments, we would end up using a lot of ledger lines:

<Ledger lines are quite difficult to read>, so the clef is changed to suit the pitch of the music at any particular point.